共查询到20条相似文献,搜索用时 15 毫秒
1.
本文介绍纯整Ehresmann半群.纯整Ehresmann半群是一类特殊的U-半富足半群,我们给出了这类半群的若干刻划,并讨论了一些特殊的纯整Ehresmann半群. 相似文献
2.
We study a class of special strongly rpp semigroups, namely, the class of super rpp semigroups. These super rpp semigroups
are generalizations of both superabundant semigroups and Clifford semigroups within the class of rpp semigroups. In particular,
we prove that a super rpp semigroup is a semilattice of D
(l)-simple strongly rpp semigroups. Our result not only generalizes a well-known theorem of Clifford in the class of completely
regular semigroups but also strengthens some structure theorems obtained by Ren-Shum for superabundant semigroups which are
orthodox. Some special super rpp semigroups are considered and discussed. 相似文献
3.
Limin Wang 《Southeast Asian Bulletin of Mathematics》2001,25(2):335-344
We characterize E-solid semigroups with inverse transversals and some special such semigroups in terms of congruences. Some properties of inverse congruences over completely simple semigroups are obtained.1991 MR Subject Classification: 20M10This work was supported by the Natural Science Foundation of Guangdong, China. 相似文献
4.
XiLin Tang 《中国科学 数学(英文版)》2010,53(11):3015-3026
It is well known that the subclass of inverse semigroups and the subclass of completely regular semigroups of the class of regular semigroups form the so called e-varieties of semigroups. However, the class of regular semigroups with inverse transversals does not belong to this variety. We now call this class of semigroups the ist-variety of semigroups, and denote it by IST. In this paper, we consider the class of orthodox semigroups with inverse transversals, which is a special ist-variety and is denoted by OIST. Some previous results given by Tang and Wang on this topic are extended. In particular, the structure of free bands with inverse transversals is investigated. Results of McAlister, McFadden, Blyth and Saito on semigroups with inverse transversals are hence generalized and enriched. 相似文献
5.
We introduce the concept of presentation for subsemigroups of finitely generated commutative semigroups, which extends the
concept of presentation for finitely generated commutative semigroups. We show that for every subsemigroup of a finitely generated
commutative semigroup there are special presentations which solve the word problem in the given subsemigroup. Some properties
like being cancellative, reduced and/or torsion free are studied under this new point of view.
This paper was supported by the project DGES PB96-1424. 相似文献
6.
给出了左C-半群的另一种结构,所谓左交错积结构,并刻画了它的特殊情形.这种结构为左C-半群在广义正则半群类中的再推广奠定了基础. 相似文献
7.
Abundant Semigroups with a Multiplicative Adequate Transversal 总被引:6,自引:0,他引:6
Xiao Jiang Guo 《数学学报(英文版)》2002,18(2):229-244
The aim of this paper is to investigate abundant semigroups with a multiplicative adequate transversal. Some properties and
characterizations for such semigroups are obtained. In particular, we establish the structure of this class of abundant semigroups
in terms of left normal bands, right normal bands and adequate semigroups with some simple compatibility conditions. Finally,
we apply this structure to some special cases.
Received February 25, 1999, Revised November 22, 1999, Accepted December 9, 1999 相似文献
8.
众所周知,Clifford半群是正则半群类中的一类重要半群,本文定义正规 Ehresmann型wrpp半群,它是Clifford半群在wrpp半群类中的推广,给出了此类半群的若干刻划. 相似文献
9.
10.
A. R. Rajan 《Semigroup Forum》1993,46(1):160-167
The theory of topological semigroups has emerged as a separate discipline during the fifties (cf. Hofmann and Mostert [5]
and Carruth, Koch and Hildebrant [3]), but the idea of topologically consistent regularity in such semigroups does not seem
to have gained much attention. In this paper topological regular semigroups are introduced where the regularity is topologically
consistent. The topological version of the structure theorem for regular semigroups given by Nambooripad [7] is provided here.
Some special cases are also discussed. The necessary terminology on topological groupoids are available in Brown and Hardy
[1] and Mackenzie [6]. 相似文献
11.
Alexander McLeman 《Semigroup Forum》2015,90(1):189-206
After reviewing automaton semigroups, we introduce Cayley automata and the corresponding Cayley automaton semigroups. We investigate which semigroups are isomorphic to their Cayley automaton semigroup and give some results for special classes of semigroups. We answer a question posed by Cain relating to the dual construction. 相似文献
12.
Mark Kambites 《Semigroup Forum》2007,74(2):159-190
We consider the preservation of the properties of automaticity and prefix-automaticity in Rees matrix semigroups over semigroupoids
and small categories. Some of our results are new or improve upon existing results in the single-object case of Rees matrix
semigroups over semigroups. 相似文献
13.
In this paper, we intrnduce the notation pmin,pmin p^min and p^min, by which we describe the trace classes and the kernel classes of general congruence p on orthodox semigronps.Then we have given and proved some equivalent characterizations of special congruences by mean of kernels and traces. On the basis of above-mentioned congruences, we further investigate theirrelations. Some results shout congruences on iverse semigroups are generalized to orthodox semigroups. 相似文献
14.
Xiangfei Ni 《Semigroup Forum》2009,78(1):34-53
The concept of quasi-adequate transversals is introduced. Some properties and characterizations for abundant semigroups with
a multiplicative quasi-adequate transversal are obtained. In particular, a structure theorem for such abundant semigroups
is given. Finally, some special cases are considered.
This research was partially supported by the National Natural Science Foundation of China (No. 10571077) and the Natural Science
Foundation of Gansu Province (No. 3ZS052-A25-017). 相似文献
15.
A. V. Kelarev 《Semigroup Forum》1991,43(1):291-298
It is well-known that semigroups of many important classes are decomposable into bands of their subsemigroups with more “rigid”
structure. For efficient applications of radicals to semigroups of that kind, an information on the shape of radicals in bands
of semigroups may be useful. Here we will investigate the Jacobson, Baer, Brown-McCoy and the least special radicals. The
results were announced in [3]. The interaction of bands and radicals was also considered in [4] for the class of semigroups
with zero; analogous problems for bands and radicals of associative rings were investigated in [5], [6] and [7]. 相似文献
16.
In this paper,the concept of right adequate transversals of rpp semigroups is introduced.We establish the structure of rpp semigroups with multiplicative right adequate transversals in terms of right normal bands and right adequate semigroups.In particular, some special cases are considered. 相似文献
17.
本文在纯正半群上首先引入了关系ρmin,ρmax,ρmin和ρmax,刻划了纯正半群上一般同余的迹类。然后利用核-迹方法给出了纯正半群上几类特殊同余的等价刻划。在此基础上,进一步研究了各类同余间的相互联系,把逆半群上有关同余的若干结果推广到纯正半群上。 相似文献
18.
We give examples of convolution semigroups on the positive half-line and on the real line. Such semigroups are expressed in
terms of special functions which arise in classical differential equations. 相似文献
19.
We consider the class of weakly U-abundant semigroups satisfying the congruence condition (C) containing both the class of regular semigroups and the class of abundant semigroups as its subclasses. The class of weakly U-abundant semigroups with a medial projection satisfying the congruence condition (C) will be particularly studied. This kind of semigroups will be called medial weakly U-abundant semigroups. In this paper, we establish a structure theorem for such semigroups. It is proved that every medial weakly U-abundant semigroup can be expressed by some kind of bands and quasi-Ehresmann semigroups. Our theorem generalizes and enriches the structure theorem given by M. Loganathan in 1987 for regular semigroups with a medial idempotent. 相似文献
20.
The structure of left C-rpp semigroups 总被引:21,自引:0,他引:21
This paper studies the class of left Clifford-rpp semigroups and investigates the structure of their semi-spined products
and semilattice decompositions. These semigroups are generalizations of left Clifford semigroups and Clifford-rpp semigroups.
We also discuss some special cases such as when a semilattice decomposition becomes a strong semilattice decomposition and
a semi-spined product becomes a spined product.
Communicated by Boris Schein
This research is jointly supported by a grant of National Natural Science Foundation of China and a small project grant #200.600.380
of CUHK. 相似文献